Lobomycosis, also known as Lobo's disease, blastomycosis, and keloidal blastomycosis, is a chronic, localized infection of the sub-epidermis characterized by the presence of keloidal, verrucoid, or nodular lesions. The causative organism, Loboa loboi, is a unicellular, spheroidal to lemon shaped, yeast like organism, 5 to 12 u in diameter. This organism has only been identified in man and two species of dolphins, Tursisops truncatus and Sotalia quianensis. In February of 1980, an adult female bottlenose dolphin, Tursiop truncatus, was collected as a breeding animal in the Indian River on the east coast of Florida. At the time of collection, a 3 an X 3 an whitish, elevated nodular growth was observed on the lower left side of the anterior rostrum. Biopsies taken on four separate occasions from 1981 to 1989 failed to identify the cause of the skin lesions. Histopathologic diagnosis was chronic dermatitis of unknown etiology. Special staining and cultures also failed to identify the cause of the lesions. To rule out the possibility of an auto-immune etiology, anti-dolphin IgG antibodies were produced in rabbits to test the lesional skin of the dolphin for the presence of immune complexes. Imamo-fluorescent staining of the biopsies was negative. In February of 1988, the animal was transported to Sea World of Texas, San Antonio, Texas from Sea World of Florida, Orlando, Florida. During the winter of 1988/89, the lesion spread rapidly over the rostrum, head, and throat area. Biopsies taken in August of 1990 demonstrated organisms identified as Loboa loboi. Treatment was initiated on August 30, 1990 with Itraconazole, a lipophilic molecule of the group of triazole drugs. Itraconazole was used long term at 4.6 mg/kg. The lesions on the rostrum and throat healed completely while those on the melon and axillary area had not completely resolved at the end of 15 months. This is only the second case reported in any species to have responded to medical therapy.